iaxclient

Name: iaxclient
Who: Several
Where: http://iaxclient.wiki.sourceforge.net/ 
        https://svn.sourceforge.net/svnroot/iaxclient/trunk/iaxclient/ 
        http://sourceforge.net/projects/iaxclient 
What: Voice over IP using IAX Protocol
Description: IAXClient is a fairly generic voip library that can be used both 
p2p and with the Asterisk server to reach the public phone system.